Regarding crystal colors, none of this is definitive or confirmed as the Only Color available, but lumin Crystals are usually described as a blue-white, Core crystals and the new Lift Crystal are Emerald, and the energy at least from ship weapon crystals was described as red-white in once place and blue-white in another (but that may be a matter of calibration, as the heat vs explosive force of their output is variable). Also Cavendish's necklace crystal is red, though as far as I understand they dont really need or have a specific purpose with an Etherealist using them.